The Sun| Mercury| Venus| Earth| Mars| Jupiter| Saturn| Uranus| Neptune| Pluto

Find all the information you need about our corner of the universe at Discover The Planets!

Discover The Planets
The Sun    (+)
Mercury    (+)
Venus    (+)
Earth    (+)
Mars    (+)
Jupiter    (+)
Saturn    (+)
Uranus    (+)
Neptune    (+)
Pluto    (+)

Uranus
Missions to Uranus
Uranus Sign/Name
Uranus Short Facts
Uranus Pictures
Uranus Moons
   -  Cordelia
   -  Ophelia
   -  Bianca
   -  Cressida
   -  Desdemona
   -  Juliet
   -  Portia
   -  Rosalind
   -  Belinda
   -  Puck
   -  Miranda
   -  Ariel
   -  Umbriel
   -  Titania
   -  Oberon
   -  Caliban
Uranus Summary

Uranus

Uranus Moon: Umbriel!

The southern hemisphere of Umbriel displays heavy cratering in this Voyager 2 image, taken Jan. 24, 1986, from a distance of 557,000 kilometers.


Discovered by William Lassell in 1851, Umbriel is the 13th moon of Uranus. Umbriel is the darkest of Uranus' larger moons and the one that appears to have experienced the lowest level of geological activity. It has a diameter of about 1,200 km and reflects only 16 percent of the light striking its surface; in the latter respect, Umbriel is similar to lunar highland areas. Umbriel is heavily cratered but lacks the numerous bright-ray craters seen on the other large Uranian satellites; this results in a relatively uniform surface albedo (reflectivity).

The prominent crater on the terminator (upper right on image) is about 110 km across and has a bright central peak. The strangest feature in this image (at top) is a curious bright ring, the most reflective area seen on Umbriel. The ring is about 140 km in diameter and lies near the satellite's equator. The puzzling bright ring in Umbriel's surface, has been nicknamed the "fluorescent cheerio."

The nature of the ring is not known, although it might be a frost deposit, perhaps associated with an impact crater. Its size and density are about the same as those of Ariel, while its surface is old with little variation in the type of terrain from one region to another. It takes Umbriel 4 days, 3 hours and 27 minutes to orbit around Uranus.


© 2017 - Discover The Planets -- 4 Jokes A Day Award Winner
Quote Fav for more!